In a prefilled syringe, a barrel is filled with a predetermined amount of drug solution in advance. A nozzle from which a liquid can be discharged is provided at a front end of a barrel body. A rubber cap or the like is put on the nozzle, and thus an opening of the nozzle is closed. A gasket is inserted slidably into the barrel body through a rear end opening of the barrel body. The drug solution or the like is contained in a space enclosed with the gasket and the barrel at a portion closer to a front end than the gasket. Since the gasket is in intimate contact with the inner surface of the barrel, the liquid-tightness of the space is maintained. When using the syringe, the drug solution can be discharged from the nozzle by removing the rubber cap from the nozzle, and pressing a plunger connected with the gasket into the barrel. By using such a prefilled syringe, time and effort required in administering medicines to patients or in mixing medicines can be reduced.
In many cases, the barrel is made of a synthetic resin. However, depending on the type of drug solution to be charged in the barrel, the barrel needs to be made of glass. In that case, unlike a barrel made of a synthetic resin, it is difficult to form a large finger flange due to the properties of glass. As a result, it is difficult to hook fingers on the flange, and thus a stable operation becomes difficult. It is also necessary to prevent breakage of the barrel during storage and transportation.
Patent document 1 discloses an injection device including a syringe and a syringe holder attached to the syringe. As shown in FIG. 14, a syringe holder 206 has an inner diameter that allows the syringe holder 206 to be attached to a cylinder tube 200 of the syringe. The syringe holder 206 includes a cylindrical holder body 207 having a length equal to the cylinder tube 200, and a finger flange 273 formed on a rear end side of the holder body 207. The finger flange 273 is formed such that its width is larger than that of a lug 222 formed on the cylinder tube 200. The syringe holder 206 includes also a fixing member 88. By sandwiching the lug 222 between the fixing member 88 and the finger flange 273, the holder body 207 is fixed to the cylinder tube 200. The sandwiching of the lug 222 is maintained by engaging first engagement protrusions 275 of the finger flange 273 with second engagement protrusions 284 of the fixing member 88.
In the injection device shown in FIG. 14, an injection needle holding portion configured of a spiral protrusion (not shown) is formed on an inner surface 271 of a front end portion of the holder body 207. Since an injection needle is fixed to the holding portion, the injection needle is prevented from dropping off from the cylinder tube 200 even when a high pressure is applied to the injection needle at the time of discharging a highly viscous medicine. Patent document 1: JP H10-155905 A